linux-toradex.git/fs/kernfs, branch v4.0.3

kernfs: handle poll correctly on 'direct_read' files.

2015-03-16T20:51:20+00:00

Kernfs supports two styles of read: direct_read and seqfile_read.

The latter supports 'poll' correctly thanks to the update of
'->event' in kernfs_seq_show.
The former does not as '->event' is never updated on a read.

So add an appropriate update in kernfs_file_direct_read().

This was noticed because some 'md' sysfs attributes were
recently changed to use direct reads.

Reported-by: Prakash Punnoor 
Reported-by: Torsten Kaiser 
Fixes: 750f199ee8b578062341e6ddfe36c59ac8ff2dcb
Signed-off-by: NeilBrown 
Acked-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

kernfs: remove KERNFS_STATIC_NAME

2015-02-14T05:21:36+00:00

When a new kernfs node is created, KERNFS_STATIC_NAME is used to avoid
making a separate copy of its name.  It's currently only used for sysfs
attributes whose filenames are required to stay accessible and unchanged.
There are rare exceptions where these names are allocated and formatted
dynamically but for the vast majority of cases they're consts in the
rodata section.

Now that kernfs is converted to use kstrdup_const() and kfree_const(),
there's little point in keeping KERNFS_STATIC_NAME around.  Remove it.

Signed-off-by: Tejun Heo 
Cc: Andrzej Hajda 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kernfs: convert node name allocation to kstrdup_const

2015-02-14T05:21:35+00:00

sysfs frequently performs duplication of strings located in read-only
memory section.  Replacing kstrdup by kstrdup_const allows to avoid such
operations.

Signed-off-by: Andrzej Hajda 
Cc: Marek Szyprowski 
Cc: Kyungmin Park 
Cc: Mike Turquette 
Cc: Alexander Viro 
Cc: Christoph Lameter 
Cc: Pekka Enberg 
Cc: David Rientjes 
Cc: Joonsoo Kim 
Acked-by: Tejun Heo 
Cc: Greg KH 
Cc: Geert Uytterhoeven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs: remove mapping->backing_dev_info

2015-01-20T21:03:05+00:00

Now that we never use the backing_dev_info pointer in struct address_space
we can simply remove it and save 4 to 8 bytes in every inode.

Signed-off-by: Christoph Hellwig 
Acked-by: Ryusuke Konishi 
Reviewed-by: Tejun Heo 
Reviewed-by: Jan Kara 
Signed-off-by: Jens Axboe

fs: deduplicate noop_backing_dev_info

2015-01-20T21:02:54+00:00

hugetlbfs, kernfs and dlmfs can simply use noop_backing_dev_info instead
of creating a local duplicate.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Jan Kara 
Acked-by: Tejun Heo 
Signed-off-by: Jens Axboe

kernfs: Fix kernfs_name_compare

2015-01-09T23:51:08+00:00

Returning a difference from a comparison functions is usually wrong
(see acbbe6fbb240 "kcmp: fix standard comparison bug" for the long
story). Here there is the additional twist that if the void pointers
ns and kn->ns happen to differ by a multiple of 2^32,
kernfs_name_compare returns 0, falsely reporting a match to the
caller.

Technically 'hash - kn->hash' is ok since the hashes are restricted to
31 bits, but it's better to avoid that subtlety.

Signed-off-by: Rasmus Villemoes 
Acked-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

vm_area_operations: kill ->migrate()

2014-12-17T13:26:51+00:00

the only instance this method has ever grown was one in kernfs -
one that call ->migrate() of another vm_ops if it exists.

Signed-off-by: Al Viro

Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2014-12-15T00:10:09+00:00

Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev__once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...

switch d_materialise_unique() users to d_splice_alias()

2014-11-19T18:01:20+00:00

Signed-off-by: Al Viro

sysfs/kernfs: make read requests on pre-alloc files use the buffer.

2014-11-07T18:54:38+00:00

To match the previous patch which used the pre-alloc buffer for
writes, this patch causes reads to use the same buffer.
This is not strictly necessary as the current seq_read() will allocate
on first read, so user-space can trigger the required pre-alloc.  But
consistency is valuable.

The read function is somewhat simpler than seq_read() and, for example,
does not support reading from an offset into the file: reads must be
at the start of the file.

As seq_read() does not use the prealloc buffer, ->seq_show is
incompatible with ->prealloc and caused an EINVAL return from open().
sysfs code which calls into kernfs always chooses the correct function.

As the buffer is shared with writes and other reads, the mutex is
extended to cover the copy_to_user.

Signed-off-by: NeilBrown 
Reviewed-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman